From the perspective of the Basketball Prospectus team, the big story during last Thursday's NBA Draft was Pittsburgh forward DeJuan Blair. Expected to be taken somewhere in the middle of the first round, Blair suffered a precipitous drop, falling all the way to the second round before the San Antonio Spurs finally ended his slide by taking him with the 37th overall pick.

Certainly, NBA scouts weren't as gung-ho about Blair's prospects as were statistical analysts. On my draft board, independent of team need, I had Blair as a top-five pick in the wake of a sophomore season that saw him shatter modern records for offensive rebounding and share Big East Player of the Year honors with No. 2 overall pick Hasheem Thabeet. Because of his size (he measured in 6'5 1/4" without shoes at the NBA's Pre-Draft Camp and pushed 300 pounds at times during his prep career), Blair has never been considered quite that kind of elite prospect.

Still, it was evident that Blair's fall had less to do with his game and more to do with another product of Pre-Draft testing--doctors "red-flagged" his physical because of Blair's knees. He underwent reconstructive surgery on both ACLs during his high-school career, and before the draft reports trickled out suggesting the possibility, seemingly preposterous, that Blair no longer had ACLs in either knee.

To get some perspective, I turned to Prospectus injury expert Will Carroll and did some additional research.

First, the idea that Blair has no anterior cruciate ligaments is a tad misleading, conjuring up a notion that he was born without them or they somehow disappeared. It is entirely possible that Blair has no working< ACLs, and this scenario is apparently not entirely uncommon for players who experience knee injuries in high school (or earlier) and do not enjoy professional treatment.

Beyond that, as remarkable as it seems, it is possible for athletes to compete, even on the highest level, without the benefit of an ACL. Most of the examples come from the NFL, including Hines Ward, who apparently tore the ACL in his left knee in a bicycle accident at age nine and was unaware he was ACL deficient until being told by a doctor at the NFL's Combine. I can find no definitive reference, but John Elway also apparently lost the use of his ACL in high school. There are also vague references to Thurman Thomas and Garrison Hearst playing after similar injuries. In MLB, pitcher R.A. Dickey was found to have no right ulnar collateral ligament (the elbow equivalent to an ACL) soon after he was drafted by the Texas Rangers, a condition that cost him considerable money in his signing bonus. Dickey has gone on to a career, albeit a minor one, in the majors, reinventing himself as a knuckleball pitcher along the way.

Because a torn ACL is such a devastating injury for athletes, it seems in some ways worse than it is. I remember being surprised to see the Seattle Storm's Shaunzinski Gortman walk out of KeyArena without a limp hours after she tore her ACL in a 2006 game. It is possible to maintain most day-to-day function without an ACL, but its absence makes lateral movement virtually impossible and destabilizes the knee. Players like Blair who have managed to overcome ACL deficiency have done so by compensating through the strength of their surrounding quadriceps muscles and hamstrings.

Part of what makes Blair unique is that he apparently does not have a working ACL in either knee. The only comparable situation I can find is former NFL cornerback Jimmy Hitchcock, who like Blair tore both ACLs during high school.

"We just didn't have the money or the medical insurance," Hitchcock told ESPN.com in 2001. "We just couldn't afford to fix 'em. Sometimes we underestimate the body's ability to adapt. I just think of it this way: What did people do before there was knee surgery?"

Hitchcock ended up enjoying an eight-year NFL career. During three years as a full-time starter, he missed just one game.

Of course, the comparison only goes so far. Hitchcock was playing a far more violent sport, but one that tests its players in game competition just once a week. Blair will have to go through the grind of an 82-game season that puts wear and tear on healthy knees. Also, while Hitchcock was listed at 5'10", 187, Blair's frame will put more stress on his knees and could cause serious cartilage problems.

So were teams too conservative in their assessment of Blair on draft night? Without complete details about his condition, it's difficult to answer that question. Still, it seems that the risk to the team drafting Blair was more of a long-term concern than an immediate one. That's an important consideration in the middle of the first round and, depending on the team that is drafting, late in it. By the time we reached the second round, however, Blair's value seemed to outweigh his knee issues--especially from our optimistic perspective on his potential as an NBA player.

Leon Powe of the Boston Celtics is a good comparison. Like Blair, Powe tore his ACL in high school, and saw his knee continue to trouble him while at California. When he was on the floor, Powe was productive, but the injuries and his size dropped him to the second round of the 2006 Draft. Sadly, the knee eventually caught up to Powe, as he tore the same ACL again during this year's playoffs. By that point, however, Powe had already contributed more than nine wins above replacement player during his first three seasons while making less than $2 million.

For the Celtics, the gamble was one well worth taking. It appears the same will be true for San Antonio as well.

Kevin Pelton is an author of Basketball Prospectus.
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